A magazine for automatic printing plate change is known from DE 43 42 359 C1. The magazine contains several printing plates to be supplied to a plate cylinder. A controllable holding device is provided for each printing plate made available in the magazine. All of the printing plates made available in the magazine are placed into the magazine vertically in a cascade-like arrangement, and their front edges are placed on the controllable holding device. Upon actuation of the holding device, it lets the front edge of the printing plate which it supports fall on a curved conveying surface. The conveying surface lets the printing plate slide to a pair of transport rollers, which transport rollers, after gripping the printing plate, convey it to the plate cylinder. The device described in DE 43 42 359 C1 has a limitation that it blocks access to the printing unit with its vertically arranged magazine and therefore makes maintenance and cleaning operations to be performed on the printing unit considerably more difficult. Because of the cascaded arrangement of the printing plates, a very long sliding path along the conveying surface to the transport rollers results for the printing plate, which is placed on the holding device and which is arranged the highest, which printing plate has to travel, only driven by gravity, after the holding device has been actuated. A curvature impressed on the flexible printing plate, by the conveying surface, is counteracted by a restoring moment resulting from the elasticity of the printing plate. This restoring moment increases friction between the printing plate and the conveying surface. The friction itself, as an energy-consuming resistance, naturally slows the sliding movement of the printing plate on the long conveying path, so that the danger arises that, because of the driving energy being used up or because of jamming, the printing plate gets stuck in the magazine. Its front edge does not dependably reach the transport rollers and therefore the printing plate cannot be dependably supplied to the forme cylinder.
A printing plate cassette for a magazine is known from DE 43 27 013 C1. The cassette seats several printing plates, and the printing plates can be pulled out of the cassette by the use of a plate removal arrangement, Spacing elements fan out the printing plates to assist in their removal in the removal area. A topmost printing plate, with its suspension legs beveled at the trailing end, of a stack of printing plates, is first supplied to a plate cylinder. There is the limitation that the printing plates stored in the magazine are spaced apart from each other by the fan-shaped removal elements only in the removal area. Accordingly, the printing plates to be fed to the cylinder are not stored completely without contact surfaces in spaced-apart storage positions, so that the danger of damage to their surfaces exists, and in particular exists when the printing plates are pulled out of the magazine. Also, feeding of only those printing plates arranged in the upper part of the magazine is possible.
A feeding arrangement for the automatic draw-in of flexible printing plates is known from DE 42 39 895 A1, by the use of which it is possible to feed a printing plate, that is located at the bottom of a stack, and which is inclined to a greater or lesser extent in respect to a horizontal line, by use of separating and feed rollers, which grasp the front area of the plate, to a printing cylinder assigned to a forme cylinder, or to an intermediate cylinder, or to a transfer drum of a sheet-fed printing press. At least the forme cylinder, the printing cylinder and the intermediate cylinder each have a gripper system for grasping the end, which is not beveled, of the fed-in printing plate. Only printing plates without a beveled suspension leg at their trailing ends can be conveyed out of the magazine by use of the separating and feed rollers of this feeding arrangement.
A method and a device for the automatic feeding of a printing plate to a plate cylinder, or for the removal of a printing plate from a plate cylinder of a rotary printing press, are known from DE 39 40 795 A1. The method for the automatic feeding of a printing plate to a plate cylinder of a rotary printing press, wherein inter alia the plate cylinder has structure for clamping and for bracing the printing plate, provides that the printing plate is placed into a storage chamber of a printing plate supply and removal device, that the plate cylinder is rotated into a plate feeding position, and that the printing plate is fed to a clamping device of the plate cylinder by operation of a number of transport rollers. The method for the automatic removal of a printing plate from a plate cylinder of a rotary printing press, wherein the plate cylinder inter alia has structure for unclamping and for releasing the printing plate, is distinguished in that the plate cylinder is rotated forward into a printing plate release position, that a clamping flap is opened for grasping a printing plate end, that the plate cylinder is rotated backward, and that the printing plate is conveyed by a number of transport rollers to a storage chamber of a printing plate supply or removal device. The device for executing the method has at least one transport roller configured as a drive roller, and one transport roller configured as a contact pressure roller, and wherein the contact pressure roller can be placed against the drive roller. In addition, various actuating devices, a pivotably seated contact pressure roller for pressing the printing plate against the plate cylinder, as well as ejection fingers, can be provided. The ejection fingers can have tips which are arranged so that they can swivel into the periphery of the plate cylinder. The storage chamber of the printing plate supply and removal device can also be seated so that it is pivotable around a joint.
DE 39 40 796 A1 describes an arrangement for automatically changing a printing plate on a plate cylinder of a rotary printing press, The plate cylinder has, inter alia, devices for clamping and for bracing a printing plate. The printing plate changing device has two storage chambers, so that a printing plate, released from the plate cylinder, can be conducted into one of the storage chamber by the use of transport rollers, while a printing plate stored in the other storage chamber can be conducted to a clamping device of the plate cylinder also by use of transport rollers.
EP 1 084 839 A1 describes a device for holding and for conveying a printing forme. In this case, the device has translatory conveying arrangements, which convey a printing forme to be mounted on a forme cylinder, or which convey a printing forme to be removed from the plate cylinder. For changing a printing forme, the device is tilted around an axis of rotation from a position of rest into its operating position. A hook is pivoted, merely by its inherent weight, into the space where the printing forme is stored and protects the printing forme at its trailing beveled end from unintentionally falling out of this space.
A device for the automatic feeding of a printing plate to a forme cylinder of a printing press, or for removing a printing plate from a forme cylinder, is known from EP 0 214 549 B1. The printing plate to be fed to the forme cylinder is fed to the forme cylinder while remaining in a desired position by the use of lateral positioning elements. The feeding of the printing plate takes place from a substantially horizontal storage position.
A device for automatically exchanging printing plates is known from EP 0 100 779 A1. Several plates to be mounted are suspended in a plate storage device on a clamping rod which is arranged below the plate cylinder and are lifted to the plate cylinder on the clamping rod.
A device for automatically changing printing plates is known from WO 03/04863 A1. Several printing formes are stored in a magazine, and a changing of a printing forme with a forme cylinder takes place only when the magazine is brought into a slanted position.
A device for the automatic feeding of printing formes to a forme cylinder is known from U.S. Pat. No. 4,178,848. Printing formes without beveled ends are stored in a stack inclined in the feeding direction, and are sequentially fed, driven by rollers, to the forme cylinder via a conveyor belt arranged in front of the stack. The lowest printing forme is pulled from the stack, at its front end, by a suction device. This device, which is very long, is not suitable for printing formes with beveled ends. Furthermore, when pulling out the printing formes which are stacked directly on top of each other, there is the danger of damaging their sides which are provided with the print image.